Modelling neuronal dysfunction in early onset epilepsies; a patient-centric approach

许多婴儿在生命的第一年就患有癫痫，不幸的是导致严重残疾和寿命缩短。一种形式的癫痫被称为“婴儿癫痫伴迁移性局灶性发作（EIMFS）”，其中受影响的婴儿具有非常频繁的癫痫发作，通常每天高达60次，通常对目前可用的药物没有反应。三个基因KCNT1、SLC12A5和SCN2A的异常可导致EIMFS。这些基因在大脑中制造重要的蛋白质，当这些蛋白质异常时，会导致婴儿癫痫发作。然而，目前还不清楚它们是如何导致癫痫的。使用一种新的最先进的脑细胞模型，该模型由从研究中的患者身上提取的皮肤细胞制成，我将研究这些基因的异常如何导致癫痫和患者的发育问题。每个患者的皮肤细胞都将被转化为干细胞。干细胞具有转化为体内任何细胞类型的潜力。一旦干细胞形成，基因编辑技术将用于纠正某些细胞中的突变。这将使我能够验证我们在异常神经元中看到的效应仅仅是由于KCNT1，SLC12A5或SCN 2A的异常而不是由于其他基因。干细胞将被转化为三维结构或类器官，成熟后几个月将由神经元层组成，有效地迷你大脑。这些迷你脑主要含有兴奋性中子。兴奋性中子引起大脑兴奋，而抑制性神经元减慢或阻止大脑兴奋。我将把一些干细胞转化成3D的抑制性神经元集合，它们将与类器官融合在一起。这是为了确保所有正确类型的神经元都存在，并且它们可以彼此形成连接。我将测试脑细胞的电特性以及它们如何与其他脑细胞连接。如果我们能精确地找出异常基因是如何引起癫痫发作的，这可能有助于我们找到治疗这种癫痫和其他癫痫的更好的药物。作为项目的一部分，我还将测试一种基因疗法，在脑细胞中缺失的基因的正常拷贝被替换。此外，我还将测试一种不同的治疗方法，“反义寡核苷酸”。寡核苷酸是一种短的合成DNA链，它具有它试图结合的DNA的镜像代码（反义）。设计反义寡核苷酸以阻断和消除异常突变的DNA。我的目的是提高我们对这些异常基因如何导致癫痫和发育问题的理解，这将有助于开发新的治疗方法，最终目的是提高我的患者及其家人的生活质量。

Many babies present with epilepsy in the first year of life, sadly resulting in severe disability and shortened lifespan. One form of epilepsy is known as "Epilepsy of Infancy with Migrating Focal Seizures (EIMFS)" in which affected babies have very frequent seizures, often up to sixty per day, which usually do not respond to currently available medications. Abnormalities in three genes, known as KCNT1, SLC12A5 and SCN2A can cause EIMFS. These genes make important proteins in the brain that, when abnormal, cause seizures in young babies.However, it is not clear how they lead to epilepsy. Using a new state-of-the art brain cell model made from skin cells taken from patients in the study, I will investigate how abnormalities in these genes lead to epilepsy and developmental problems in patients. Skin cells from each patient will be converted into stem cells. Stem cells have the potential to convert into any of the cell types in the body. Once the stem cells are formed, gene editing technology will be used to correct the mutation in some of the cells. This will allow me to verify that the effect we see in the abnormal neurones is just due to the abnormality in KCNT1, SLC12A5or SCN2A and not due to other genes. The stem cells will be converted into three dimensional structures or organoids which after maturation for several months will be made up of layers of neurons, effectively mini-brains. These min-brains contain mostly excitatory neutrons. Excitatory neutrons cause brain excitation, whereas inhibitory neurons slow down or prevent brain excitation. I will convert some of the stem cells into 3D collections of inhibitory neurons which will be fused together with the organoids. This is to ensure all the correct types of neurons are present and that they can form connections with each other. I will test the electrical properties of the brain cells and how they connect with other brain cells. If we can work out precisely how the abnormal genes cause seizures, this may help us identify better drugs for both this form of epilepsy and other epilepsies. As part of the project I will also test a form of gene therapy, where a normal copy of the gene is replaced in the brain cell where it is missing. In addition, I will also be testing a different treatment, "antisense oligonucleotides". An oligonucleotide is a short synthetic DNA strand which has the mirror image code (antisense) of the DNA it is trying to bind to. The antisense oligonucleotide is designed to block and inactivate the abnormal mutated DNA. My aim is to improve our understanding of how these abnormal genes lead to epilepsy and development problems which will help in the development of new treatments, with the ultimate aim of improving quality of life for my patients and their families.